Multi-nozzle nozzle and droplet ejection device

Abstract

A method for manufacturing a multi-nozzle printhead includes: preparing a substrate having multiple recesses on its upper side; forming a seed metal layer on the upper side of the substrate and the multiple recesses; forming an insulator at the bottom of the multiple recesses in the seed metal layer using an electrostatic inkjet method; forming a first metal layer in the exposed portion of the seed metal layer; forming a photoresist pattern on the first metal layer and the insulator; forming a second metal layer in the exposed portion of the first metal layer; removing the photoresist pattern, the insulator, and the seed metal layer overlapping the insulator to form a nozzle orifice; and processing the substrate.

Description

Technical Field

[0001] This invention relates to a multi-nozzle nozzle, a method for manufacturing a multi-nozzle nozzle, and a droplet ejection device. Prior Technology

[0002] In recent years, inkjet printing technology has been applied to industrial processes. For example, the manufacturing process of color filters for liquid crystal displays is one such application. While piezoelectric printheads, which eject droplets through mechanical pressure or vibration, have been commonly used in inkjet printing, electrostatic inkjet printheads capable of ejecting even finer droplets have attracted considerable attention. Patent Document 1 discloses an electrostatic inkjet recording apparatus.

[0003] Patent Documents Patent Document 1: Japanese Patent Publication No. H10-34967 Summary of the Invention

[0004] Recently, from the perspective of improving productivity, multi-nozzle printheads have been developed for use in electrostatic inkjet printheads. However, in multi-nozzle printheads, there is a risk of poor nozzle opening formation, making it difficult to uniformly form the nozzle opening. Therefore, a method for stably forming the nozzle opening is being sought.

[0005] Therefore, one object of the present invention is to provide a method for manufacturing a multi-nozzle nozzle capable of stably forming a nozzle opening. Furthermore, another object of the present invention is to uniformly eject liquid droplets.

[0006] According to one embodiment of the present invention, a method for manufacturing a multi-nozzle printhead is provided, comprising: preparing a substrate having an upper side and a lower side opposite to the upper side and having a plurality of recesses on the upper side; forming a seed metal layer on the upper side of the substrate and the plurality of recesses; forming a first insulator at the bottom of the plurality of recesses in the seed metal layer using an electrostatic inkjet method; forming a first metal layer in the exposed portion of the seed metal layer; forming a second insulator on the seed metal layer and the first insulator; forming a second metal layer in the exposed portion of the first metal layer; removing the second insulator, the first insulator, and the seed metal layer overlapping the first insulator to form a nozzle opening; and processing the substrate.

[0007] In the above-mentioned method for manufacturing multi-nozzle nozzles, the size of the first insulator can be 1 μm or more and 100 μm or less.

[0008] In the above-mentioned method for manufacturing multi-nozzle printheads, a mask formed by electrostatic inkjet printing can also be used when forming the aforementioned second insulator.

[0009] In the above-mentioned method for manufacturing a multi-nozzle nozzle, the diameter of the nozzle opening can also be adjusted according to the amount of the first insulator ejected.

[0010] In the above-mentioned manufacturing method of multi-nozzle nozzle, etching can also be used to remove the metal seed layer that overlaps with the first insulator.

[0011] In the above-mentioned manufacturing method of multi-nozzle nozzles, wet etching can also be used to remove the metal seed layer that overlaps with the first insulator.

[0012] In the above-mentioned manufacturing method of multi-nozzle nozzle, the metal seed layer overlapping with the first insulator can also be removed by peeling method.

[0013] In the above-mentioned manufacturing method of multi-nozzle nozzles, the thickness of the aforementioned metal seed layer can be 10 nm or more and 100 nm or less.

[0014] In the above-mentioned manufacturing method of the multi-nozzle nozzle, the thickness of the first metal layer can be more than 1 μm and less than 10 μm, and the thickness of the second metal layer can be more than 10 μm and less than 100 μm.

[0015] In the above-mentioned method for manufacturing multi-nozzle nozzles, the aforementioned substrate can also be processed to form a separator that maintains the distance between the substrate and the target object being sprayed.

[0016] In the above-described method for manufacturing a multi-nozzle nozzle, an electrode can also be formed that contacts a portion of the aforementioned separator and has an opening corresponding to the aforementioned nozzle opening.

[0017] According to one embodiment of the present invention, a multi-nozzle nozzle can be provided, comprising: a plate portion having a through hole; a droplet ejection nozzle portion having a plurality of droplet ejection nozzles disposed corresponding to the through hole of the plate portion and having a plurality of droplet ejection nozzles ejecting droplets in an electrostatic ejection manner; a pseudo-nozzle portion having a plurality of pseudo-nozzles disposed around the droplet ejection nozzle portion in the plate portion and having a plurality of pseudo-nozzles with closed ends; and a separator disposed on the end side of the droplet ejection nozzle in the plate portion and configured to maintain a distance from the target object from which the droplets are ejected.

[0018] In the aforementioned multi-nozzle nozzle, the aforementioned separator may also have: a column portion that contacts the aforementioned plate portion, and a flat plate portion that is disposed opposite to the aforementioned plate portion and contacts the aforementioned column portion.

[0019] The aforementioned multi-nozzle nozzle may also include an electrode disposed on the aforementioned separator in a manner that faces the aforementioned droplet ejection nozzle.

[0020] According to one embodiment of the present invention, a droplet ejection device may be provided, comprising: the above-described multi-nozzle nozzle.

[0021] By using one embodiment of the present invention, a method for manufacturing a multi-nozzle nozzle capable of stably forming a nozzle opening can be provided. Furthermore, by using one embodiment of the present invention, droplets can be uniformly ejected. Simple Explanation of the Diagram

[0022] Figure 1 is a schematic diagram of a droplet ejection device according to one embodiment of the present invention.

[0023] Figure 2A is a top view of a multi-nozzle nozzle according to one embodiment of the present invention.

[0024] Figure 2B is a cross-sectional view of a multi-nozzle nozzle according to one embodiment of the present invention.

[0025] Figure 3 is an enlarged top view of a multi-nozzle nozzle according to one embodiment of the present invention.

[0026] Figure 4 is a perspective view of a droplet ejection nozzle according to one embodiment of the present invention.

[0027] Figure 5A is a top view of a droplet ejection nozzle related to one embodiment of the present invention.

[0028] Figure 5B is a cross-sectional view of a droplet ejection nozzle according to one embodiment of the present invention.

[0029] Figure 6A is a top view of a pseudo-nozzle related to one embodiment of the present invention.

[0030] Figure 6B is a cross-sectional view of a pseudo-nozzle related to one embodiment of the present invention.

[0031] Figure 7A is a manufacturing process diagram of a multi-nozzle nozzle related to one embodiment of the present invention.

[0032] Figure 7B is a manufacturing process diagram of a multi-nozzle nozzle related to one embodiment of the present invention.

[0033] Figure 7C is a manufacturing process diagram of a multi-nozzle nozzle related to one embodiment of the present invention.

[0034] Figure 8A is a manufacturing process diagram of a multi-nozzle nozzle related to one embodiment of the present invention.

[0035] Figure 8B is a manufacturing process diagram of a multi-nozzle nozzle related to one embodiment of the present invention.

[0036] Figure 8C is a manufacturing process diagram of a multi-nozzle nozzle related to one embodiment of the present invention.

[0037] Figure 9A is a manufacturing process diagram of a multi-nozzle nozzle related to one embodiment of the present invention.

[0038] Figure 9B is a manufacturing process diagram of a multi-nozzle nozzle related to one embodiment of the present invention.

[0039] Figure 10A is a manufacturing process diagram of a multi-nozzle nozzle related to one embodiment of the present invention.

[0040] Figure 10B is a manufacturing process diagram of a multi-nozzle nozzle related to one embodiment of the present invention.

[0041] Figure 11A is a manufacturing process diagram of a multi-nozzle nozzle related to one embodiment of the present invention.

[0042] Figure 11B is a manufacturing process diagram of a multi-nozzle nozzle related to one embodiment of the present invention.

[0043] Figure 12 is a cross-sectional view of a multi-nozzle nozzle according to one embodiment of the present invention.

[0044] Figure 13 is a cross-sectional view of a multi-nozzle nozzle according to one embodiment of the present invention.

[0045] Figure 14 is a cross-sectional view of a multi-nozzle nozzle according to one embodiment of the present invention. Implementation

[0046] The following description, with reference to the accompanying drawings, illustrates various embodiments of the invention disclosed in this application. However, the invention may be implemented in various forms without departing from its spirit and is not limited to the description of the embodiments exemplified below.

[0047] Furthermore, in the drawings referenced in this embodiment, the same or similar symbols are used to mark the same parts or parts with the same function (only symbols such as A, B, or -1, -2, etc. are marked after the numbers), and repeated descriptions are sometimes omitted. Also, the size ratios in the drawings may sometimes differ from the actual ratios or omit parts of the structure from the drawings for ease of explanation.

[0048] Furthermore, in the detailed description of this invention, when specifying the positional relationship between a structure and other structures, the terms "above" and "below" do not only include the case where it is located directly above or below a certain structure. Unless otherwise specified, they are considered to include the case where there are other structures in between.

[0049] <First Embodiment>

[0050] (1-1. Structure of the droplet ejection device 100)

[0051] Figure 1 is a schematic diagram of a droplet ejection device 100 according to one embodiment of the present invention.

[0052] The droplet ejection device 100 includes: a control unit 110, a memory unit 115, a power supply unit 120, a drive unit 130, a droplet ejection unit 140, and a target support unit 160.

[0053] The control unit 110 includes a CPU (Central Processing Unit), ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), or other computing circuits. The control unit 110 uses a pre-set droplet ejection program to control the ejection process of the droplet ejection unit 140.

[0054] The memory unit 115 functions as a database for storing the droplet ejection program and various information used in the droplet ejection program. Memory unit 115 can use memory, SSD (Solid State Drive), or other memory-enabled components.

[0055] The power supply unit 120 is connected to the control unit 110, the drive unit 130, and the droplet ejection unit 140. The power supply unit 120 applies voltage to the droplet ejection unit 140 according to the signal input from the control unit 110. In this example, the power supply unit 120 applies a pulsed voltage (1000 V in this example) to the droplet ejection unit 140. In addition, a constant voltage can be continuously applied without being limited to the pulsed voltage. By means of the voltage applied from the power supply unit 120 to the multi-nozzle printhead 150, the liquid stored in the ink tank 145 is ejected from the multi-nozzle printhead 150 in the form of droplets from the end portion 153a of the droplet ejection nozzle 153 (see Figure 2B) towards the target object 200 in the direction (third direction D3).

[0056] The drive unit 130 is composed of drive components such as an electric motor, belt, and gears. Based on the instructions from the control unit 110, the drive unit 130 moves the droplet ejection section 140 (more specifically, the multi-nozzle head 150 described later) relative to the target support section 160 in one direction (in this example, the second direction D2). Furthermore, the drive unit 130 can also fix the droplet ejection section 140 while moving the target object. Additionally, the drive unit 130 can be used in conjunction with a goniometer to finely adjust the position of the multi-nozzle head 150.

[0057] The droplet ejection section 140 includes an ink reservoir 145 and a multi-nozzle printhead 150. An electrostatic inkjet nozzle can be used in the multi-nozzle printhead 150. Details of the multi-nozzle printhead 150 will be described later. The multi-nozzle printhead 150 is fixed to a mounting base and attachment (not shown). The mounting base and attachment may also have grooves (elongated holes) in the portion corresponding to the droplet ejection nozzle 153 for temporarily storing ink supplied from the ink reservoir 145.

[0058] The target support portion 160 functions to support the target object 200. In this example, a platform can be used for the target support portion 160. The mechanism by which the target support portion 160 supports the target object 200 is not particularly limited, and a general support mechanism can be used. In this example, the target object 200 is vacuum-adsorbed onto the target support portion 160. Furthermore, not limited to this, the target support portion 160 can also use a fixing tool to support the target object 200.

[0059] (1-2. Structure of the multi-nozzle nozzle 150)

[0060] The structure of the multi-nozzle nozzle 150 is described in detail below. Figure 2A is a top view of the multi-nozzle nozzle 150. Figure 2B is a cross-sectional view of the multi-nozzle nozzle 150 between C1 and C2. Figure 3 is an enlarged view of the top view of the multi-nozzle nozzle 150. Figure 4 is a perspective view of the droplet ejection nozzle 153. Figure 5A is a top view of the droplet ejection nozzle 153. Figure 5B is a cross-sectional view between A1 and A2 in the droplet ejection nozzle 153. Figure 6A is a top view of the dummy nozzle 155. Figure 6B is a cross-sectional view between B1 and B2 in the dummy nozzle 155.

[0061] As shown in Figures 2A and 2B, the multi-nozzle nozzle 150 includes: a plate portion 151, a droplet ejection nozzle portion 152, and a pseudo-nozzle portion 154.

[0062] The plate portion 151 is plate-shaped. The plate portion 151 extends along the first direction D1. A metallic material such as nickel can be used in the plate portion 151. The thickness of the plate portion 151 can be appropriately set. In this example, the thickness of the plate portion is 10 μm or more and 100 μm or less.

[0063] As shown in Figures 4, 5A, and 5B, a droplet ejection nozzle portion 152 is provided on one side of the plate portion 151 (in this example, the lower side). The droplet ejection nozzle portion 152 includes a plurality of droplet ejection nozzles 153. The droplet ejection nozzles 153 are arranged along a first direction D1. In this embodiment, droplet ejection nozzles 153-1, 153-2, ..., 153-(N-1), and 153-N are provided on the plate portion 151. N is a natural number of 20 or more. In this example, N=21. Furthermore, without distinguishing between droplet ejection nozzles 153-1, 153-2, ..., 153-(N-1), and 153-N, the description will focus on droplet ejection nozzles 153. The droplet ejection nozzles 153 can be made of a metal material such as nickel. The droplet ejection nozzles 153 have a tapered shape at the tip.

[0064] The plate portion 151 has a through hole 151o in the portion (overlapping portion) corresponding to the droplet ejection nozzle 153. The through hole 151o has an inner diameter r151o larger than the inner diameter r153a of the outlet of the droplet ejection nozzle 153 (the opening 153ao of the end portion 153a of the droplet ejection nozzle 153). The inner diameter r151o of the through hole 151o of the plate portion 151 can be 1 μm or more and 1 mm or less, preferably 10 μm or more and 100 μm or less. The inner diameter r153a of the end portion 153a of the droplet ejection nozzle 153 can be several hundred nm or more and 500 μm or less, preferably 1 μm or more and 100 μm or less, more preferably 3 μm or more and 50 μm or less, and even more preferably 5 μm or more and 20 μm or less. In this embodiment, voltage can be applied to the droplet ejection nozzle 153, the plate portion 151 (or the ink tank 145), or the liquid (ink). When voltage is applied to the plate portion 151 or the droplet ejection nozzle 153, electrodes can also be provided. The electrodes can be made of materials such as tungsten, nickel, molybdenum, titanium, gold, silver, copper, or platinum. In this case, multiple electrodes can be provided to uniformly apply voltage to the entire plate portion 151. Furthermore, although this embodiment discloses an example of applying voltage to the droplet ejection nozzle 153, the plate portion 151, or the ink, voltage can also be applied to the fixture (e.g., mounting base and attachment) supporting the multi-nozzle printhead 150.

[0065] As shown in Figure 2B, a dummy nozzle portion 154 is disposed within the plate portion 151 on the same surface as the droplet ejection nozzle portion 152. The dummy nozzle portion 154 includes a plurality of dummy nozzles 155. The dummy nozzle portion 154 is disposed around (outer) the droplet ejection nozzle portion 152. In this example, the dummy nozzle portion 154 is disposed on both sides of the first direction D1 in which the droplet ejection nozzle portion 152 is disposed. Furthermore, the plurality of dummy nozzles 155 can also be disposed in a designated area starting from the outermost dummy nozzle 155 (dummy nozzle 155-L1 in this example). From the viewpoint of the electric field strength in the peripheral portion, the plurality of dummy nozzles 155 can also be disposed in an entire area extending from the outermost dummy nozzle 155 toward the first direction D1, covering a range of 1 mm or more and 5 mm or less (preferably 2 mm). At this time, the number of dummy nozzles 155 provided on one side of the droplet ejection nozzle section 152 in the first direction D1 can be more than 1 / 5 of the number of droplet ejection nozzles 153. For example, the number of dummy nozzles 155 provided on one side of the droplet ejection nozzle section 152 in the first direction D1 can be more than 5 and less than 50, preferably more than 10 and less than 30. In this embodiment, a left dummy nozzle 155L containing 5 dummy nozzles 155 (dummy nozzles 155-L1 to 155-L5) is provided on the left side of the droplet ejection nozzle section 152 which contains 21 droplet ejection nozzles 153. Similarly, a right dummy nozzle 155R containing 5 dummy nozzles 155 (dummy nozzles 155-R1 to 155-R5) is provided on the right side of the droplet ejection nozzle section 152. Furthermore, since it is not necessary to distinguish them as dummy nozzles 155-L1 to 155-L5, they will be described in the form of dummy nozzle 155.

[0066] As shown in Figure 3, the distances between adjacent droplet ejection nozzles (the distance between droplet ejection nozzle 153-1 and droplet ejection nozzle 153-2) dis1, the distances between adjacent droplet ejection nozzle 153 and dummy nozzle 155 (the distance between droplet ejection nozzle 153-1 and dummy nozzle 155-L5) dis2, and the distances between adjacent dummy nozzles 155 (the distance between dummy nozzle 155-L4 and dummy nozzle 155-L5) dis3 are all the same. In this example, the distances between each nozzle dis1, dis2, and dis3 are 200 μm.

[0067] As shown in Figures 6A and 6B, the end portion 155a of the dummy nozzle 155 is closed and has no opening. Therefore, the dummy nozzle 155 does not eject droplets. In this example, the dummy nozzle 155 is filled to the same height as the upper part of the plate portion 151. The same material as the droplet ejection nozzle 153 can be used for the dummy nozzle 155. The dummy nozzle 155 can also have the same shape as the droplet ejection nozzle 153. In this case, the height H155 of the dummy nozzle 155 (also referred to as the first height, specifically the height from the lower side 151a of the plate portion 151 to the end portion 155a of the dummy nozzle 155) can also be the same as the height H153 of the droplet ejection nozzle 153 (also referred to as the second height, specifically the height (vertical distance) from the lower side 151a of the plate portion 151 to the end portion 153a (the horizontal plane of the end portion 153a) of the droplet ejection nozzle 153).

[0068] Therefore, when using a multi-nozzle nozzle containing multiple nozzles to eject droplets via electrostatic spraying, the electric field may sometimes be larger in the peripheral region of the plate compared to the center. In the case of the multi-nozzle nozzle 150 of this embodiment, a dummy nozzle section 154 is arranged around the droplet ejection nozzle section 152. In short, multiple dummy nozzles 155 are arranged in the region where the electric field is larger. Since the ends 155a of the multiple dummy nozzles 155 are blocked, droplets will not be ejected. On the other hand, the electric field in the region where the droplet ejection nozzles 153 are arranged becomes uniform. This makes the size of the droplets ejected by each droplet ejection nozzle 153 more uniform.

[0069] (1-3. Manufacturing method of multi-nozzle nozzle 150)

[0070] The manufacturing method of the multi-nozzle nozzle 150 is illustrated in the figures. Figures 7A to 11B are cross-sectional views showing the manufacturing process of the multi-nozzle nozzle.

[0071] First, as shown in FIG7B, a substrate 2000 having a plurality of recesses for forming a droplet ejection nozzle 153 and a dummy nozzle 155 is prepared. In this embodiment, the substrate 2000 has a first surface (upper surface) 2000A and a second surface (lower surface) 2000B opposite to the first surface 2000A. The substrate 2000 includes a first substrate 2001 and a second substrate 2005. Furthermore, on the first surface 2000A side, a plurality of first recesses 2007 for forming a droplet ejection nozzle are provided, and a plurality of second recesses 2009 are provided around the first recesses 2007 for forming a dummy nozzle.

[0072] The substrate 2000 can be formed by film formation, photolithography, or etching. Specifically, as shown in FIG7A, a first substrate 2001 is prepared to be plate-shaped. The first substrate 2001 can also be a metal substrate, a semiconductor material, or a conductive film formed on the side of an insulating substrate or a semiconductor substrate.

[0073] Next, as shown in Figure 7B, a second substrate 2005 is formed on the first substrate 2001. The second substrate 2005 can also be formed by photolithography and etching after the insulating layer is formed. At this time, the first substrate 2001 is exposed at the bottom of the first recess 2007 and the second recess 2009.

[0074] Furthermore, although the above describes an example of forming the second substrate 2005, the present invention is not limited thereto. For example, multiple recesses can also be formed on the first substrate 2001 using photolithography and etching methods.

[0075] Next, as shown in Figure 7C, a metal seed layer 2100 is formed on the first surface 2000A side of the substrate 2000, including the first recess 2007 and the second recess 2009, using a physical vapor deposition method such as sputtering. The metal seed layer 2100 is used as a seed layer for the first metal layer 2300. From the viewpoint that the thickness of the metal seed layer 2100 is sufficient to form both the first metal layer and the nozzle orifice, it is preferably 10 nm or more and 100 nm or less.

[0076] Next, as shown in Figure 8B, an insulator 2200 (also referred to as the "first insulator") is formed at the bottom 2007b (more specifically, the center of the bottom 2007b) of the first recess 2007 in the metal seed layer. At this time, the droplet 2200a, which becomes the insulator 2200, as shown in Figure 8A, can be ejected by a single-point electrostatic inkjet nozzle 300. The size of the insulator 2200 is preferably 1 μm or more and 100 μm or less. The size of the multi-nozzle depends on the size of the insulator 2200. Therefore, the viscosity of the ejected droplet (ink) 2200a is preferably 0.1 cps or more and 10,000 cps or less, and preferably 0.5 cps or more and 1,000 cps or less. With the above viscosity, it becomes easier to control the size of the droplet 2200a. Furthermore, the amount of droplet ejected can be adjusted as desired. This allows for adjustment of the nozzle opening size.

[0077] In this embodiment, there are no particular restrictions on the material of the droplet, as long as it is an insulating material. In this example, polyimide resin (polyimide varnish), solder resist, photosensitive resin, etc., can also be used as the insulating material. Furthermore, the material of the droplet can be not only an insulating material, but also a semiconductor material.

[0078] Next, as shown in Figure 8C, a first metal layer 2300 is formed in the exposed portion of the seed metal layer 2100. The first metal layer 2300 can be formed by electrolytic casting (electroplating). The thickness of the first metal layer 2300 is preferably 1 μm or more and 10 μm or less. At this time, the first metal layer 2300 is formed in the exposed portion of the seed metal layer 2100 in the first recess 2007, but not in the portion where the insulator 2200 is formed. On the other hand, the first metal layer 2300 is formed entirely in the second recess 2009.

[0079] Next, as shown in Figure 10A, an insulator 2400 (also referred to as the "second insulator") is formed on the portion of the first metal layer 2300 and the insulator 2200 corresponding to the droplet ejection nozzle 153. First, as shown in Figure 9A, an insulating layer 2400a is formed on the first metal layer 2300 and the insulator 2200. The insulating layer 2400a contains a resin material. While the method for forming the insulating layer 2400a is not particularly limited, from the viewpoint of forming the second metal layer 2500 to a manageable thickness, it is desirable to form it using a coating method (specifically, a spin coating method). Alternatively, the insulating layer 2400a can also be formed by attaching a thin film of resin.

[0080] The insulating layer 2400a may also contain a photosensitive material. In this case, an insulator 2400 can be formed without forming a photoresist mask.

[0081] Next, as shown in Figure 9B, a photoresist mask 2450 is formed on the portion of the insulating layer 2400a corresponding to the droplet ejection nozzle 153 (end portion 153a). The photoresist mask 2450 can also be formed by photolithography. Alternatively, the photoresist mask 2450 can also be formed by electrostatic inkjet printing. In this case, since the photoresist mask 2450 can be formed without using a photomask, the manufacturing cost can be reduced. After the photoresist mask 2450 is formed, as shown in Figure 10A, the exposed portion of the insulating layer 2400a is removed by etching until the first metal layer 2300 is exposed, thereby forming the insulator 2400.

[0082] Next, as shown in Figure 10B, a second metal layer 2500 is formed in the portion exposed within the first metal layer 2300. The material of the second metal layer 2500 can be the same as that of the first metal layer 2300. The second metal layer 2500 can be formed by electrolytic casting (electroplating). From the viewpoint of processing multi-nozzle nozzles, the thickness of the second metal layer 2500 is desirable to be 10 μm or more and 100 μm or less.

[0083] Next, as shown in Figure 11A, the photoresist mask 2450 and the insulator 2400 are removed. The photoresist mask 2450 and the insulator 2400 can be removed by stripping or etching using organic solvents or other chemical solutions.

[0084] Next, as shown in Figure 11B, the insulator 2200 and the (overlapping) metal seed layer 2100 located beneath the insulator 2200 are removed. The insulator 2200 can also be removed by stripping or etching using organic solvents or other chemical solutions. The metal seed layer 2100 can also be removed by etching. In this example, the metal seed layer 2100 is removed by wet etching. When the metal seed layer is nickel, it can be removed using a solution containing hydrogen peroxide. At this time, even if the materials of the metal seed layer 2100, the first metal layer 2300, and the second metal layer 2500 are the same, the thickness of the metal seed layer 2100 is very thin compared to the thickness of the first metal layer 2300 and the second metal layer 2500. Therefore, the variation in the thickness of the first metal layer 2300 and the second metal layer 2500 is small, so the impact on the shape of the multi-nozzle nozzle 150 is small. Thus, a portion corresponding to the nozzle opening 153ao is formed. Furthermore, by using wet etching, the removal of the metal seed layer 2100 and the cleaning of the nozzle opening 153ao can be carried out in one step.

[0085] Finally, the substrate 2000 (second substrate 2005) is removed from the seed metal layer 2100 (release molding). Through the above, a multi-nozzle nozzle 150 can be manufactured.

[0086] In the above-described process, when the first metal layer 2300 and the second metal layer 2500 are formed on the substrate 2000 using electrolytic casting, the electric field in the edge region of the substrate 2000 tends to become non-uniform. However, in this embodiment, the edge region of the substrate 2000 is the region where the pseudo-nozzle is formed. Therefore, the electric field in the region where the droplet ejection nozzle 153 is formed becomes uniform. This further allows the shape of the droplet ejection nozzle 153 to make the opening shape of the end portion 153a more uniform.

[0087] Furthermore, in this embodiment, by using electrostatic inkjet printing for the portion corresponding to the nozzle opening 153ao, a small-sized insulator 2200 can be uniformly formed. At this time, by removing the insulator and the metal seed layer, multiple nozzle openings can be stably and uniformly formed.

[0088] Therefore, by using this embodiment, a method for manufacturing a multi-nozzle nozzle capable of stably forming the nozzle opening can be provided. Furthermore, by using the multi-nozzle nozzle of this embodiment, droplets can be sprayed uniformly.

[0089] <Second Embodiment>

[0090] In this embodiment, a multi-nozzle nozzle 150A that differs from the first embodiment will be described. Specifically, a multi-nozzle nozzle with a separator as described in the first embodiment and an example of forming such a multi-nozzle nozzle will be described. Furthermore, for the sake of description, components already described in the first embodiment will be appropriately omitted.

[0091] Figure 12 is a cross-sectional view of the multi-nozzle nozzle 150A. As shown in Figure 12, the multi-nozzle nozzle 150A includes a plate portion 151, a droplet ejection nozzle portion 152 (droplet ejection nozzle 153), a dummy nozzle portion 154 (dummy nozzle 155), and a separator 157. The separator 157 is columnar. The separator 157 is disposed on the end portion 153a of the droplet ejection nozzle 153 in the plate portion 151. The separator 157 is configured to maintain the distance between the multi-nozzle nozzle 150A and the target object 200, which is the target of the ejection. By having the separator 157, the distance between the multi-nozzle nozzle 150A and the target object 200 becomes constant, and the potential difference during droplet ejection is made uniform. Therefore, droplets can be ejected uniformly.

[0092] The process of forming the opening 153ao in the multi-nozzle nozzle 150A is the same as in the first embodiment. Next, spacers 157 are formed between adjacent droplet ejection nozzles 153, between droplet ejection nozzles 153 and dummy nozzles 155, and between adjacent dummy nozzles 155, by processing the substrate 2000 using etching or grinding methods. In this embodiment, the spacers 157 can be formed by processing the substrate 2000 of the first embodiment, thus simplifying the manufacturing of the multi-nozzle nozzle 150A.

[0093] <Third Embodiment>

[0094] In this embodiment, a multi-nozzle nozzle 150B that differs from the first embodiment will be described. Specifically, a multi-nozzle nozzle having a separator and a plate-shaped electrode attached to the separator in the first embodiment will be described. Furthermore, for the sake of description, components already described in the first and second embodiments will be appropriately omitted.

[0095] Figure 13 is a cross-sectional view of the multi-nozzle nozzle 150B. As shown in Figure 13, the multi-nozzle nozzle 150B includes an electrode 159 in addition to the plate portion 151, the droplet ejection nozzle portion 152 (droplet ejection nozzle 153), the dummy nozzle portion 154 (dummy nozzle 155), and the separator 157. The electrode 159 is arranged in a shape corresponding to the separator 157, facing the droplet ejection nozzle 153. In this example, the electrode 159 may also be arranged in a flat plate shape. In this case, the electrode 159 is engaged on the side opposite to the side that contacts the plate portion of the separator 157. The electrode 159 has an opening 159o at a position corresponding to the end portion 153a (opening portion 153ao) of the droplet ejection nozzle 153. A conductive material can be used for the electrode 159.

[0096] Furthermore, in this embodiment, the distance between the droplet ejection nozzle 153 and the electrode 159 is constant. This allows a constant voltage to be applied between the droplet ejection nozzle 153 and the electrode 159. Therefore, droplets can be uniformly ejected onto the target object 200.

[0097] Furthermore, although this embodiment discloses an example of electrode 159 being configured as a flat plate, the present invention is not limited thereto. The separator 157 and electrode 159 can also be formed integrally. In this case, the separator 157 can also be joined to the plate portion 151 of the multi-nozzle head 150B.

[0098] Furthermore, the shape of the electrode 159 can also be different. As shown in Figure 14, the multi-nozzle head 150C includes a separator 157C and an electrode 159C in addition to the plate portion 151, the droplet ejection nozzle 153, and the dummy nozzle 155. The separator 157C includes a column portion 157Ca and a plate portion 157Cb. The column portion 157Ca is columnar. The plate portion 157Cb is plate-shaped. One side of the column portion 157Ca contacts the plate portion 151. The other side of the column portion 157Ca contacts the plate portion 157Cb. In this case, the electrode 159C can also be disposed in contact with the plate portion 157Cb of the separator 157C in a manner that faces the droplet ejection nozzle 153 (end portion 153a). The electrode 159C can also be disposed in a ring shape. The opening 153ao of the end portion 153a of the droplet ejection nozzle 153, the opening 159Co of the electrode 159C, and the opening 157Co of the plate portion 157Cb are arranged in a corresponding manner. In addition, the electrode 159C can also be arranged to contact the lower side of the plate portion 157Cb of the separator 157C.

[0099] (Modified Example)

[0100] Within the scope of this invention, any modifications and alterations that are conceived by those skilled in the art are also considered within the scope of this invention. For example, regarding the foregoing embodiments, any appropriate additions, deletions, combinations, or design changes to the constituent elements, or additions, omissions, or changes to the processing, by those skilled in the art, are also included within the scope of this invention, provided they capture the essence of the invention.

[0101] In the first embodiment of the present invention, an example is disclosed in which droplets 2200a, which are formed into insulators 2200, are ejected from a single-point electrostatic inkjet nozzle. However, the present invention is not limited thereto. For example, after manufacturing the initial multi-nozzle printhead, the manufacturing of subsequent multi-nozzle printheads can also be performed using the first multi-nozzle printhead. In this way, since droplets can be ejected from each nozzle of the multi-nozzle printhead, the manufacturing speed of the multi-nozzle printhead can be increased.

[0102] Furthermore, when the liquid droplets are ejected as the insulator 2200 in the first embodiment of the present invention, the camera can also move along with the electrostatic inkjet nozzle. In this way, the position of the ejected droplets can be captured in advance, and the position of the electrostatic inkjet nozzle can be corrected if the position of the ejected droplets deviates.

[0103] Furthermore, the ejection status of the droplets can be inspected through the photographic section after the droplets are ejected from the first recess 2007. In this case, the first droplet can be removed and the droplets can be ejected again where ejection defects have occurred.

[0104] In one embodiment of the present invention, the insulator 2400 is not limited to a resin material. For example, the insulator 2400 may also be an inorganic insulating material.

[0105] In the first embodiment of the present invention, although an example of removing the metal seed layer 2100 by wet etching is disclosed, the present invention is not limited thereto. For example, depending on the material of the metal seed layer, it can also be removed by dry etching. Furthermore, the metal seed layer can also be removed by stripping when removing the insulator 2200. This simplifies the manufacturing process of multi-nozzle nozzles.

[0106] 100: Droplet ejection device 110: Control Department 115: Memory Department 120: Power Supply Department 130: Drive Unit 140: Droplet ejection section 145: Inkwell 150: Multi-nozzle spray head 150A: Multi-nozzle spray head 150B: Multi-nozzle spray head 150C: Multi-nozzle spray head 151: Plate section 151a: Lower side 151o: Through hole 152: Droplet ejection nozzle section 153: Droplet ejection nozzle 153-1~N: Droplet ejection nozzle 153a: End portion 153ao: Opening 154: Pseudo-nozzle section 155: Pseudo-nozzle 155a: End portion 155L: Left pseudo-nozzle 155-L1~5: Pseudo-nozzle 155R: Right pseudo nozzle 155-R1~5: Pseudo-nozzle 157: Separator 157C: Separator 157Ca: Column 157Cb: Flat plate section 157Co: Opening 159: Electrode 159C: Electrode 159Co: Opening 159o: Opening 160: Target support section 200: Target 300: Electrostatic Ejection Inkjet Nozzle 2000: Substrate 2000A: Side 1 (Top Side) 2000B: Side 2 (Bottom Side) 2001: First Substrate 2005: Substrate No. 2 2007: 1st recess 2007b: Bottom 2009: 2nd recess 2100: Metal Seed Layer 2200: Insulator 2200a: Droplet 2300: First metal layer 2400: Insulator 2400a: Insulation layer 2450: Photoresist mask 2500: Second metal layer dis1, dis2, dis3: Distance D1: Direction 1 D2: Second Direction D3: 3rd direction H153: Height H155: Height r151o:inner diameter r153a:inner diameter

Claims

1. A multi-nozzle nozzle comprising: a plate portion having a through hole; a droplet ejection nozzle portion having a plurality of droplet ejection nozzles disposed corresponding to the through hole of the plate portion and having a plurality of droplet ejection nozzles ejecting droplets in an electrostatic ejection manner; a pseudo-nozzle portion having a plurality of pseudo-nozzles disposed around the droplet ejection nozzle portion in the plate portion and having a plurality of pseudo-nozzles with closed ends; and a separator disposed on the end side of the droplet ejection nozzles in the plate portion and configured to maintain a distance from the target object from which the droplets are ejected, wherein the separator is configured such that the distance between the multi-nozzle nozzle and the target object is constant, and is configured such that the potential difference when the droplets are ejected is uniform based on the constant distance.

2. The multi-nozzle nozzle as claimed in claim 1, wherein the aforementioned separator has: a column portion that contacts the aforementioned plate portion, and a flat plate portion that is disposed opposite to the aforementioned plate portion and contacts the aforementioned column portion.

3. The multi-nozzle nozzle as claimed in claim 1, comprising: an electrode disposed on the aforementioned separator in a manner opposite to the aforementioned droplet ejection nozzle.

4. A droplet ejection device comprising: a multi-nozzle nozzle as described in claim 1.

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